How to Improve the Reproduction Rate of Small Tail Han Sheep

Small-tailed Han sheep, which is a kind of animal under the subfamily Bovidae and Sheep subfamily, is a dual-purpose sheep breed for meat and fur in China. It has the advantages of rapid growth, early maturity, strong fecundity, stable genetic performance and strong adaptability. It is regarded as the "national treasure" of China, "super sheep" and "high-legged sheep" in the world. And was included in the "national livestock and poultry genetic resources conservation catalogue". It is not only one of the best projects for farmers to shake off poverty and become well-off, but also the safest project for the government to help the poor, and it is also an important measure for the country to close mountains and return farmland, recommend raising sheep and build ecological agriculture. Precisely because of the particularity of small-tailed Han sheep, the benefit of breeding small-tailed Han sheep is considerable, and there are more and more people, so breeding technology is the key, so how to improve the reproduction rate of small-tailed Han sheep?

Choose multi-lamb rams and ewes to keep seed.

Double lambs or multiple lambs are hereditary, and the previous generation of rams and ewes had better be selected from the reserve flock of more than one twin lamb. These rams and ewes with good genetic basis can give full play to their genetic potential and improve the probability of multiple lambs in ewes.

Strengthen the nutrition of breeding sheep

Strengthening the nutrition of breeding sheep is an important measure to improve the reproduction rate. Adequate nutrition makes the breeder sheep have a healthy body condition and moderate fatness, the ram maintains a strong libido, and the semen has a large number of sperm, strong vitality and high fertilization ability during mating; ewes can be in estrus all the year round, and the healthy fetus develops well after mating pregnancy. the postpartum milk is sufficient, the lamb is born big, the survival rate is also high, at the same time, the probability of poor fertility of ewes will increase. Therefore, raising small-tailed Han sheep, whether grazing or house feeding, must be fed with sufficient mixed concentrate. During the non-mating period, ewes were required to be fed 0.5 kg of mixed concentrate per day, 0.8-1.0 kg of mixed concentrate and 1.7-1.8 kg of roughage during the breeding period, and 0.3-0.4 kg of mixed concentrate per day for ewes. Pregnant ewes should gradually increase the amount of concentrate with the increase of the days of pregnancy (especially in the later stage). Concentrate must contain sufficient protein, energy, vitamins, trace elements and other minerals, and ensure adequate drinking water. Green feed is especially important for breeding sheep. Because the green feed can make up for the deficiency of nutrition in the concentrate and roughage, it plays an important role in increasing the sperm density and vitality of the ram, promoting the maturation and multiple ovulation of the eggs in the ewe, increasing the probability of giving birth to many lambs, and promoting the development and growth of the fetus in the pregnant ewe. it plays an important role in ensuring the birth of lambs and high survival rate.

Increase the proportion of young and middle-aged ewes in the flock

In the flock, the fecundity of young ewes, old and weak ewes is lower than that of adult ewes. According to statistics, small-tailed Han sheep give birth to less single lambs, generally only in the first birth, while the proportion of double lambs is higher. In the ewe's life, the reproduction rate is the highest at the age of 3-4 years, and the breeding period is generally 8 years. Therefore, in order to improve the overall level of the flock, adjust the flock structure reasonably, supplement the young ewes in a planned way, appropriately increase the proportion of ewes aged 3-4 years in the flock, and find and eliminate the old, weak or low fecundity ewes in time, it has become a problem that animal husbandry writers face and must solve, and on this basis, the goal of improving the overall reproduction rate of sheep can be achieved.

Carry out twice mating

When ewes are in estrus, the implementation of double mating or twice insemination can improve the quasi-pregnancy rate of ewes and increase the probability of giving birth to twin lambs. because ewes have a short time of estrus (usually about 30 hours) and the survival time of ova is shorter, and some ewes have different maturation time, so the probability of one-time mating or insemination of ewes is low, and it is difficult to make more eggs participate in fertilization. By using the method of twice mating, the spermatozoa with fertilization ability can be kept in the reproductive tract of ewes and the chance of fertilization can be increased. The method commonly used in production is that ewes who confirm estrus are inseminated once after 12 and 24 hours, and the interval between two insemination is 10-12 hours, which can effectively improve the conception rate of ewes.

Early weaning of lambs

Timely early weaning of lambs and shortening of lactation time of ewes can promote ewes to have early estrus and achieve one-year productivity. Early weaned lambs need to artificially train their feeding ability and feed some fresh grass, vegetable leaves or soft and digestible hay and leaves at 10-15 days of age to stimulate the early formation of digestive function of lambs and the transition to independent feeding of lambs. In order to make the lamb eat as soon as possible, at the beginning, you can cook porridge with corn and bean noodles or mix it in water to let the lamb eat. You can also put the fried concentrate in a basin and let the lamb lick it. Generally, the lamb can eat normally after 20ml.

Injection of drugs or hormones to induce ewes to produce more lambs

A substance which can promote ovarian follicular maturation and multiple ovulation was injected into ewes at a certain dose to strengthen the sexual function of ewes through hormone regulation, so as to promote the development and maturation of ewes eggs, so as to produce more eggs to participate in fertilization. to achieve the goal of multiple lambs. According to the experiment, the injection of pregnant horse serum or double lamb and twin placenta has a certain effect on inducing ewes to give birth to many lambs.

Induce estrus and superovulation

Estrus can be induced by "ram effect" or increasing light time to achieve the purpose of early estrus, and reproductive hormones can also be used to induce ewe estrus and superovulation in order to induce multiple lambs. Anestrus ewes or newly weaned ewes can be injected with progesterone (such as progesterone 150 mg 300 mg) into the cervix (or injection of progesterone 10 mg 12 mg / day), and then injected with pregnancy horse serum 500 IU and chorionic gonadotropin 300 IU after 14 days, to promote ewe estrus and ovulation, so as to achieve the purpose of inducing lambs. Ewes with normal estrus can be injected intramuscularly with 300 IUs of pregnant horse serum 4 days before the expected arrival of estrus (that is, the 12th-13th day of the estrous cycle). After estrus, injection of 200 million international units of chorionic gonadotropin can promote ewe to estrus and ovulate more, so as to achieve the goal of producing more lambs.